Traditionally, agricultural products such as hay, grain, silage, field crops and the like have been stored in permanent structures. Barns, sheds, silos and other permanent structures erected near the fields in which the crops are produced have typically been utilized for such purposes.
Although permanent structures are generally weatherproof and provide secure storage for agricultural products, there exist numerous drawbacks to their use. In addition to the relatively high cost of constructing and maintaining such structures, specialized equipment is often required to load or unload agricultural products therefrom. Considerable labor is also involved in handling and transporting agricultural products between the fields and such fixed storage facilities. For example, hay grown in a particular field may later be used to feed livestock grazing in the same field, requiring transport to and from a permanent storage facility. The use of remotely located storage structures thus involves unnecessary handling of the agricultural products, which is both time consuming and expensive in terms of labor cost. Additionally, permanent storage structures are generally not sealed or airtight, contributing to shrinkage, spoilage and losses in the nutritional value of agricultural product stored therein.
More recently, temporary structures have been developed for the storage of agricultural products. For example, agricultural storage bags have been used in conjunction with silage compression apparatus for in-field storage of agricultural products, thus eliminating the need for permanent storage facilities and the expenses associated therewith. An important benefit deriving from the use of agricultural storage bags involves the ability to provide airtight storage, thus eliminating the losses in the nutritional value of stored agricultural products characterized by other storage techniques.
Agricultural storage bags actually comprise large diameter, elongate, flexible plastic tubes. For example, a typical agricultural storage bag may have a diameter of up to 9 feet or more and a length of up to 135 feet or more. Agricultural storage bags are folded prior to shipment, and are thereafter mounted on the housing or tunnel of a silage compression machine in the folded condition. The silage compression machine functions to feed and compress agricultural material into the agricultural storage bag. As material is fed into the storage bag, the silage compression machine slowly moves away from the built up mass of compressed material, thereby pulling the bag off of the rear of the tunnel of the silage compression machine.
U.S. Pat. No. 4,424,051, granted to Richard H. Lee, Steven R. Cullen, Eddie H. Bailen, David H. Rasmussen and William C. Johnson on Jan. 3, 1984, relates to a method of and apparatus for manufacturing two-ply agricultural storage bags. In accordance with the method disclosed therein, each bag accumulates on a horizontally disposed table as assembly progresses. This causes the bag to form into a series of accordion-like folds, that is, a series of folds each extending perpendicularly to the longitudinal axis of the bag. In actual practice, it has been found that superior results are obtained when agricultural storage bags are formed into so-called "flat folds", that is, folds extending parallel, rather than perpendicular, to the longitudinal axis of the bag. Specifically, flat folded bags are easier to install on the tunnel of a silage compression machine prior to use and tend to pull off of the tunnel of a silage compression machine during silage compression operations more uniformly than is the case with bags folded in an accordion-like manner.
The present invention relates to a method of and apparatus for forming flat-folded agricultural storage bags. In accordance with the broader aspects of the invention, an agricultural storage bag is advanced longitudinally until the leading end thereof surrounds an annular pad. A plurality of lower arms, which are disposed circumferentially about the lower end of the annular pad, are then extended to engage the exterior of the bag, thereby gripping the leading end of the bag against the annular pad. A plurality of upper arms are disposed circumferentially about the upper end of the annular pad. The upper arms are extended to fold the unsecured portion of the bag trailing the leading end thereof over the lower arms, thereby gripping the first fold of the bag and the leading end thereof against the annular pad. The lower arms are then withdrawn from between the leading end of the bag and the first fold and are thereafter immediately reextended to engage the exterior of the first fold, thereby gripping the first fold and the leading end of the bag against the annular pad. The foregoing steps a repeated until the entire length of the agricultural storage bag has been accumulated in a plurality of flat folds. The bag is then secured in the folded condition and removed from the apparatus.